Denver ? After days of delays, a rescue flight reached the South Pole on Saturday to pick up an ailing worker at a research station there.

Snow and wind delayed the rescue attempt for five days while the plane waited at British Rothera Air Station on Antarctica, 1,346 miles from the pole.

The flight from Rothera to the pole took about eight hours. The crew planned to stay overnight at the Amundsen-Scott South Pole Station and leave at 5 a.m. CDT, said Valerie Carroll, spokeswoman for Raytheon Polar Services, the Colorado company that manages the polar station.

The rescuers will fly the employee back to Rothera and then to the southern tip of Chile for the return flight to the United States.

If weather blocks the return flight to Rothera, the plane will fly 800 miles to McMurdo Station on the coast of Antarctica to rendezvous with a U.S. military aircraft from New Zealand, said Peter West of the National Science Foundation.

The ill employee, whose name is being withheld at his request, is ambulatory but may need surgery. Raytheon has declined to confirm reports he is suffering from a bladder infection.

The rescue plane is a Twin Otter, a rugged twin-engine plane designed for rough weather, and capable of landing on small landing strips.

It is the third such rescue in four years, and is occurring in darkness. The sun doesn’t come up at the South Pole until Tuesday when the southern hemisphere spring arrives.